!

ISSN 0126-5539

- .' PERSATUAN GEOLOGI MALAYSIA

NEWSLETTER OF THE GEOLOGICAL SOCIETY OF MALAYSIA

Ji1 5, no. 5 (Vol. 5, no. 5) KDN 0717/79 Sept-Oct 1979

KANDUNGAN (CONTENTS)

CATITAN GEOLOGI (GEOLOGICAL NOTES)

K.R. Chakraborty: Spinel lherzolite inclusion in 1imburgi te from Kuantan., Pahang 63

B.K. Lim: The nature of the contact between the 'quartz porphyry' and the Jerai Formation in the Rest House area, Gunung Jerai, Kedah 67

MESYUARAT PERSATUAN (MEETINGS OF THE SOCIETY)

GSM Geotechnical Engineering Seminar, 1979 (abstracts of papers)

BERITA-BERITA PERSATUAN (NEWS OF THE SOCIETY)

New Library Additions Membership Change of address

BERITA-BERITA LAIN (OTHER NEWS)

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78 78 78

Ninth AnnuaL Convention, Indonesian Petroleum Association 79 Forthcoming books on Earth Sciences 79 Travel grants for Geoscientists 79 Calendar 80

~L..:-. ISSUED BIMONTHLY BY THE ~O~ GEOLOGIC·AL SOCIETY OF MALAYSIA ~\.6}Jf c/o Jabatan Geologi, Universiti Malaya, ~··~W""1"'· Kuala Lumpur 22-11, Malaysia. Dicetak oleh Yam's Lino Setters Sdn. Bhd., 23, Jln Brunei Barat, K.L.

, \

NBSATUAN GEOLOGI MALAYSIA (GEOLOGICAL SOCIETY OF MALAYSIA)

Presiden (President)

Naib-Presiden (Vice-President)

Setiausaha Kehormat (Hon. Secretary)

Penolong Setiausaha (Hon. Asst. Secretary)

Bendahari (Treasurer)

Pengarang (Editor)

Majlis . (Council) 197$/80

Pegawai-pegawai (Officers)..

Tan Bock Kang, Jabatan Geologi, Universiti Mal aye., It ual a LUlnpur" --. --=-- .- ...• -

Khoo Teng Tiong, Jabatan Geologi, Univer-si ti Malaya, Kuala Lumpur.

Wong Yoke Fah, Valdun Mining Consultants, P .0. Box 242, Kual a Lumpur.

Khoo Kay Khean, Jabatan Penyiasatan Kaji-bumi, Ban gun an Ukor, Jalan Gurney, Kual a Lumpur.

Gan Ah Sai, Jab at an Penyiasatan Kajibumi, Bangunan Ukor, Jalan Gurney, Kuala Lumpur.

Ahmad Jantan, Jabatan Geologi, Universiti Kebangsaan Malaysia, Kuala Lumpur.

*****

Ahli-ahli Majlis (Councillors)

James, Lau, Petronas, Peti Surat 2444, Kuala Lumpur. Mohd. Ali Hassan, Jabatan Geologi, Universi ti Malaya, Kuala Lumpur. Abdul Aziz Hussin, Jabatan Kejuruteraan Petroleum, Universiti

Teknoloji Malaysia, Kuala Lumpur. Tan Boon Kong, Jabatan Geologi, Universi ti Kebgansaan Malaysia,

Kual a Lumpur. S.S. Subramani am , Killinghall Tin, Peti Surat 202, Puchong, Selangor. Khalid Ngah, Carigali Petronas, Peti Surat 2407, Kuala Lumpur. Chin Lik Suan, 13 Lorong SSl/llA, Kampong Jamil Rais, Petaling Jaya. Leong Khee Meng, Pet ron as , Peti Surat 2444, Kuala Lumpur.

*****

63

GEOLOGICAL NOT E S

Spinel lherzolite inclusion in limburgite from Kuantan, Peninsular Malaysia.

K.R. Chakraborty, Jabatan Geologi, Universiti Malaya, Kuala Lumpur.

Inclusions of mantle-derived ultramafic xenoliths are quite common in undersaturated alkaline mafic lavas of both continental and oceanic regions (see, for example, Forbes and Kuno, 1965). Such xenoliths have also been reported from the Late Cenozoic alkaline basaltic province of Southeast Asia that covers Thailand, Kampuchea, Laos and Vietnam (Barr and MacDonald, 1978). But ultramafic xenoliths have not hitherto been reported from the alkaline basaltic lavas of Kuantan which also probably belong ~o this basaltic province.

Alkaline lavas of Kuantan comprise three distinct types, namely, alkali olivine basalt, limburgite (basanite) and olivine nephelinite (Chakraborty, 1977). These rocks are now under investiga-tion by the writer. The study began in 1977. Recently, several new thin sections of all the three lava types have been stUdied. One of the examined limburgite specimens contains a weathered (soils the finger) pale yellowish inclusion (2.5 cm x 2 cm x 0.8 cm). On microscopic examination, this inclusion was found to be a spinel lherzolite conSisting of olivine, two pyroxenes and greenish brown spinel. This inclusion is somewhat deformed and highly carbonatized. This is the first recorded occurrence of spinel lherzoli te in the Kuantan lavas. As yet, no ultramafic xenolith has been found in the alkali olivine basalt and the olivine nephelinite.

Spinel lherzolite xenoliths from alkaline basaltic lavas have been extensively studied by many workers. Phase chemistry and high pressure equilibria studies suggest equilibration of spinel lherzolith xenoliths at 800 - 11000C in the minimum pressure range of 8 to 15 kb, implying that they are, in all probability, of mantle origin (Green and Hibberson, 1970; Ringwood, 1975, p. 109). From cumUlative evidence of isotopes, REE and trace element geochemistry and textural features, most workers believe that spinel lherzolite xenoliths are accidental and not cognate (cf. O'Hara, 1968), and that they probably represent modified samples of the Upper mantle (see, for example, Frey and Green, 1974).

The presence of a dense spinel lherzolite xenolith suggests that the limburgitic (basanitic) magma of Kuantan has ascended directly and rapidly from a depth of ~ 30 km without signficant modification by crystal fractionation processes at shallower depths. (Incidentally, Kushiro, et al., 1976, have inferred, from viscosity data, that basalts carrying peridotite nodules would have to ascend from a depth of 50 km in less than 60 h.). This implies that the limburgitic magma is either primary (i.e. an unmodified partial melt of mantle peridotite) or a high pressure derivative liquid formed in mantle environment from a primary melt by crystal frac-tionation or other processes. Resolution of these two genetic

ISSN 0126-5539 Warta Geotogi~ vot. 5~ no. 5~ Sept-Oct 1979

64

alternatives is not possible with the data currently available. However, the chemical composition may throw some light on this problem. Three chemical analyses of the limburgites and their CIPW norms are presented in Table 1.

On theoretical grounds, primary melts in equilibrium with mantle peri~~tite should characteristically have high Mg-values i.e. Mg/(Mg + Fe ). In the absence of other more definitive evidence, this Mg-value has been used by some workers to identify primary magiDa. According to Frey, et ale (1978), primary basaltic magmas formed by partial melting (up to 30%) of mantle peridotite should have Mg-values hetween 68 and 75. Irving and Green (1976) put the lower limit of the Mg-~alue at 66 for primary liquids in e8fil~~rium with mantle olivines of composition Fo 6 to F090 , assuming KD v q = 0.33. The Mg-values of the analysed l~mburgites are between 65 and 68 (Table 1). It is thus tempting to infer that they may represent a primary magma. How-ever, the Mg-values have been calculated on the basis of an assumed Fe20 3/FeO ratio of 0.25. If the pre-eruptive Fe20 3/FeO ratio were less, then the Mg-values would also be somewhat lower. Moreover, the MgO contents of these limburgites appear to be less than those of the spinel lherzolite-bearing basanites (considered as primary) of other areas. Thus some fractionation of the limburgitic magma prior to entrainment of spinel lherzolite inclusion cannot be discounted.

References

Barr, S.M. and MacDonald, A.S., 1978. Geochemistry and petrogenesis of Late Cenozoic aikaline basalts of Thailand. Bull. Geol. Soc. Malaysia, 10, 25-52.

Chakraborty, K.R., 1977. Kuantan, Pahang. 3, 1-5.

Olivine nephelinite and limburgite from Warta Geologi (Geol. Soc. Malaysia Newsletter),

Forbes, R., and Kuno, H., 1965. The regional petrology of peridotite inclusions and basaltic host rocks. In Upper Mantle Symposium, New Delhi, 161-179, (Int. Union Geol. Sci).

Frey, F.A., and Green, D.H., 1974. The mineralogy, geochemistry and origin of lherzolite inclusions in Victorian basanites. Geochim. Cosmochim. Acta, 38, 1023-1059.

and Roy, S.D., 1978. Integrated models of basalt petrogenesis: a study of quartz tholeiites to olivine melilitites from South Eastern Australia utilizing geochemical and experimental petrological data. J. Petrol., 19, 463-.513.

Green, D.H., and Hibberson, W., 1970. in periddtite at high pressure.

The instability of plagioclase Lithos, 3, 209-22l~

Irving, A.J., and Green, D.H., 1976. Geochemistry and petrogenesis of the Newer' Basalts of Victoria and South Australia. J. Geo1. Soc. Australia, 23, 45-66.

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Kushiro, I., Yoder, H.S., Jr., and Mysen, B.O., 1976. of basalt and andesite melts at high pressures. Res., 81, 6351-6356.

Viscosities J. Geoph.

O'Hara, M.J., 1968. The bearing of phase equilibria studies in synthetic and natural systems on the origin and eVQiution of basic and ultrabasic rocks. E·arth-sci. Rev., 4, 69-133.

Ringwood, A.E., 1975. Composition and Petrology of the Earth's Mantle. McGraw-Hill, New York.

*****

-Table 1. Chemical analyses of limburgi tes

Oxide 1 2 3

Si02 44.88 45.59 45.38

Ti02 2.02 1.93 1.96

A1205 14.02 13.42 13.65

FeO* 10.92 11.03 10.89

MnO 0.20 0.20 0.19

MgO 9.67 9.88 10.59

CaO 9.46 9.08 9.20

Na20 3.60 3.91 3.78

K20 1.95 1.77 1.79

P205 0.S9 0.88 0.85

L.I. 2.10 1. 83 1.14

Total 99.71 99.52 99.42

100 M~ 65.92 66.17 67.96 ++ Mg+Fe

*Tota1 irOll as FeO. L.I. = Loss on ignition. All analyses by XRF. Analysis no. 3 is from the spinel lherzolite-bearing specimen.

CIPW Norm **

Or 11.77 10.68 10.73 Ab 12.30 15.49 13.43 An 16.69 14.13 15.21 Ne 10.19 9.91 10.31 Di 20.47 21.02 20.55 01 19.19 19.58 20.69 Mt 3.30 3.33 3.27 11 3.92 3.74 3.78 AI! 2.15 2.13 2.04

** Based on Fe20 3/FeO = 0.25.

67

The nature of the contact brtween the 'quartz2Porphyry' and the Jerai Formation in the Rest House area, Kedah Peak , Kedah.

Lim Beng Kung, Jabatan Geo10gi, Universiti Malaya, Kuala Lumpur.

Introduction

The origin of the quartz porphyry body in the vicinity of the Kedah Peak Rest House has been a subject of much speculation since it was first noted by Wi11bourn (1926), who believed it to be genetically related to the Jerai Granite. Paramanathan (1964) mapped it as an intrusive body. It was later referred to as an aplite dyke by Rao (1972). Minor sedimentary characteristics of the rock led Bradford (1972) to speculate a possible metasomatised arenaceous origin, while A1mashoor (1974) is more inclined towards a tuffaceous origin.

The purpose of this note is to present some new data on the relation between the 'quartz porphyry' and the Jerai Formation obtained during a recent study involving detailed geological and ground magnetic survey of the Rest House area (Fig. 1).

Stratigraphy

The major part of the area is underlain by regionally meta-morphosed metasediments of the Jerai Formation. Though they grade into one another, 3 lithological units, J 1 , J 2 and J 3 , can be differentiated based on texture, colour and mIneralogy (Fig. 2). Cross-bedding shows that there is no overturning.

J 3 , the youngest unit, is an uninterrupted sequence of 'clean' light grey to white quartzite with very little mica. Thin sections show that it is composed mainly of medium-sized, equigranob1astic polygonal quartz.

J 2 which underlies unit J 3 is predominantly made up of beds of grey to dark green quartz-mica schist. These rocks often show black laminae composed of rich concentrations of mafic minerals, epidote and biotite. They easily break along schistose planes, exposing platy white mica and tourmaline prisms. Occasional bands of large quartz grains are present in the unit.

Unit J l is a sequence of rock with predominant beds of quart-zite, often 1ron-stained. Increase in argillaceous content in the lower parts of this unit give rise to beds of quartz-mica schists similar to those in unit J 2 but with greater amount of epidote. The

sschist here grades into coarse-grained metamorphosed schist.

'Quartz pOrphyry'

Of special interest is the magnetite-veined quartz porphyry which typically consists of large crystals of relict quartz and alkali

1 Rumah Persinggahan 2 Gunung Jerai

ISSN 0126-5539 Warta GeoZogi, voZ. 5, no. 5, Sept-Oat 1979

68

Location of the area

~~--------------, LtG'NO

""-." ~ , ......... o.tioe

,. . 10 1 .s 1

.... 10 •

\------r----------,---1~

~------+_--_I 'to

\-----t--"1 ,,'

._ .. ' railway

, rood ~ river

studk?d aren

°i.,l ___ ....... _____ I..L.. ___ ....I~ kill

t

69

FIG.2 GEOLOGICAL MAP OF KEDAH PEAK RES 1 HOUSE AREA

LE6END

••• of. '.1 QUARTZ PORPHYRY

:=-:t1:':: JERAI FORMA110N -:.: -i::·

/--- GEOLOG1CAl BOUNDARY

+

+ .. t

~ ~

.--" .. ' l. ____ . i i t ~s

0 ,. I

ROAD H .' RIVER

TRAVERSE PATH

RENTIS

DIP & STRIKE

", • : .. / " .i/

.)) ,. , , f , .

... , ,. .. ""~

, ••• 1 t.

t 'j.\;- .

.. '--AEST • HOUSE t

t

.. .. t

t

"~I~~ __ -.-----"

I I I

\ \

'.

70

feldspar (microcline) in a groundmass of quartz and mica. In the magne-ti te mineralised area, there is notable increase in magnetite grains, biotite and tourmaline in the rock. The large quartz grains often show embayed features and in large handspecimensalignment of the mica is evident.

The 'quartz porphyry' bears some resemblance to the metamorphosed grit of unit J l . However, the metamorphosed grit is notably devoid of large crystals of alkali feldspar and the larger quartz grains invariably have sutured boundaries while those in the 'quartz porphyry' are euhedral.

Nature of the 'quartz pOrphyry'/Jerai Formation contact

It is interesting to note that Paramanathan (1964) and Rao (1972) mapped the f'quartz porphyry' at the Rest House as an igneous body with a lenticular outcrop and Almashoor (1974) mapped it as part of an extensive conformable bed within the Jerai Formation. However in the present detailed study, it has been found that the outcrop is not elongated but circular in outline, cutting the metasediments (Fig. 2). At location SL28 (Fig. 2), the intrusive contact can be seen in the outcrop (Plate 1).

Generally, the beds dip gently towards the north-west. Detailed mapping, however, showed that some beds near the contact do not follow the regional trend •. At location PsNW40, the quartzite beds are distorted, possibly due either to forceful intrusion or later deformation accompanying regional metamorphism.

The metamorphosed 'quartz porphyry' at the contact with the Jerai Formation has a different composition from the rock more than 30 m away from the contact. In contact with the quartzite of unit J 3 at SL28, the metamorphosed 'quartz porphyry' lacks biotite and muscovite. Butthe rocks at the contact with the schists of unit J 2 at Pl S50/W35 (ii) and SLIO are darker because of the presence of abundant biotite and muscovite. This may be due to either contact contamination before metamorphism or to metasomatism.

Ground magnetic survey

Magnetite veins were observed to occur mainly in the 'quartz porphyry' and were rarely found in the metasediments. Ground magnetic measurements reflect very well these near-surface magnetic bodies, some of which are exposed, yielding localized intense and steep-gradient anomalies. These local, intense anomalies do not die out beyond the boundary of the outcrop but continue as less intense and broader anomalies, an indication of similar but deeper magnetite veins. As there appear to be no mineralisation of any significance in the metasediments, these broader anomalies can be interpreted to indicate extensions of the 'quartz porphyry' beneath the metasediments. This interpretation is in line with the intrusive nature of the 'quartz porphyry'.

Outside the study area, about 2 km downhill from the Rest House, similar 'quartz porphyry' is exposed and probably emplaced in rocks which are likely to be older than unit J l , judging from the inclination

71

of the beds. This 'quartz porphyry' could well be an extension of the 'quartz porphyry' at the Rest House, or it could be a separate body of the same nature. Interestingly, over the area of this lower out-crop, the airborne magnetometer survey by Agocs, et al. (1958) also shows an anomaly (No.9). They interpreted the anomaly to have been caused by sources similar to the anomaly over the presently studied (Rest House) area.

Conclusion

Field and ground magnetic studies show that the 'quartz porphyry' at the Rest House area of Kedah Peak is intrusive into the Jerai Formation and is not conformable to the bedding of the Jerai Formation rocks.

Acknowledgement

I am indebted to Dr. T.T. Khoo for his guidance and encourage-ment in this project. I would also like to express my thanks to Universiti Malaya for support from the F-vote grant of Dr. T.T. Khoo. Thanks are also due to Prof. C.L. Samz of Universiti Sains Malaysia and Dr. B.K. Tan of Universiti Malaya for advice and assistance and Mr. Chow Kok Tho for his close cooperation and help in the field and laboratory.

References

Agocs, W.B. and Paton, J.R., 1958. scintillation counter survey (Area 6). Economic Bulletin tion of Malaya. 52 p.

Airborne magnetometer and over parts of Kedah and Perlis 1.6, Geological Survey, Federa-

Almashoor, S.S., 1974. The tuff of Gunung Jerai, Kedah (Abstract). Newsl.. Geol. Soc Malaysia, no. 52, p. 27.

Bradford, E.F., 1972. The geology of the Gunung Jerai area, Kedah. District Memoir 13, Geol. Survey Malaysia. 242 p.

Paramanathan, S., 1964. The geology of the Gunung Jerai Massif, south-west Kedah. Unpubl. B.Sc. (Hons) thesis, Univ. Malaya, Kuala Lumpur. 48 p.

Rao, A.K., 1972. The geology and geochemistry aspects of the southern Gunung Jerai area, Kedah, West Malaysia. Unpubl. B.Sc. (Hons) thesis, Univ. Malaya. 110 p.

Willbourn, E.S., 1926. The geology and mining resources 6f Kedah and Perlis. Jour. Mal. Br., Roy. Asiatic Soc., 4, pt. 3, 289-332.

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Plate 1. Intrusive contact between bedded quartzite (J3

) and quartz porphyry (QP). Location: SL28.

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MEETINGS o F THE SOCIETY

GSM Geotechnical Engineering Seminar, 1979

The Seminar, the first of its kind in Malaysia, was held on Saturday, 6th October 1979 at Rumah Universiti, University of Malaya.

12 papers were presented and these were grouped under soil mechanics, rock mechanics, engineering geology and special techniques.

Abstracts of papers

Stability of cut slopes on granitic residual soils.

J.K. Raj., Dept. of Geology, University of Malaya.

~e characteristics of a typicaZ residuaZ soiZ profiZe deveZoped on a granitic bedrock are first described as these features infZuence the stabiZity of sZopes cut thereupon. The types and causes of actuaZ faiZtures are then described and concZusions reached on the short and long teT'm stabiUty of cut sZopes on granitic residuaZ soiZs.

*****

Soil stabilization with natural rubber latex emulsion - an anti-soil erosion measure for exposed soil surfaces.

Soong Ngin Kwi, Rubber Research Institute of Malaysia.

ExperimentaZ investigations have shown that NR Zatex emuZsion sprayed onto exposed soiZ surfaces gave effective protection against soiZ erosion. On highZy erodibZe soiZs~ Uke Serdang and Sungei BuZoh series~ appZication of emuZsions containing 10 - 15% d~ rubber and 2 - 8% aromatic oiZ reduced soiZ Zosses by 70 - 87% when compared with the controZ. Within a period of five rrr:mths~ soa Zosses equi-vaZent to 288.6 tonnes per hectare were obtained on untreated soil surfaces~ whereas those soiZs treated with emuZsions had Zosses in the range of 36.7 - 86.6 tonnes per hea.tare. Treatment with Zatex-oiZ emuZsions aZso resuZted in reduced runoff and increased infiZtration of water. When NR Zatex emuZsion and grass cover were used together~ soiZ Zosses through erosion were aZmost compZeteZy checked.

The technique is being used commerciaZZy as an anti-erosion measure for the three major highways in Sabah. It wiZZaZso be adopted for estabZishing ZandfiZZs in the construction of the proposed Kuala Lipis - Gua MUsang Highway in PeninsuZar MaZaysia.

*****

A need for better seismic monitoring in Malaysia

Leong Lap Sau, School of Physics, Universiti Sains Malaysia, Penang.

A need arises for a better and more far-sighted seismic moni-toring program in MaZaysia. The present seismoZogical network

74

coverage is inadequate. Earthquakes with ML < 4 cannot be located. Thus rrrinor aCJtive zones outside the main beT-ts are not indicated. Although Peninsular Malaysia is not situated in a seisrrric area~ it is not irrurrune to shock waves from earrthquakes in adjacent regions. Magnitude versus acceleration and attenuation with distance plots should be used at least to de~ne acceleration levels to anchor design response spectra of high rise buildings and e:x:pensive structures.

No effort h"aS been made 80 far to "r>nitor possible induced seisrrricity by reservoir loading in recent large e:x:pensive hydroeleCJtric proje¢;s in Malaysia. Artificial loads causing stresses at 01' near the surface of the earth can engender earthquakes. Adequate rrrmitoring should be made long before~ during and after loading is initiated. Induced seisrrricity at the Manic 3 reservoir in Quebec affors an important case histozry. Six weeks after the start of filling of the Manic 3 reservoir~ a long sequence of induced earthquakes began. The main shock~ mbL = 4.1~ was prececkd by 1 rronth of foreshock act.ivity and followed oygmore than l~OOO aftershocks in the next 4 months. After 2 years~ the aCJtivity still persists. The aCJtivity appeared to have been triggered by water percolating through joint systems and along orientated planes. The presence of regional stresses and local inhomogeneities~ struCJtural and lithological~ are suggested as principal causes~ and not the dimensions of the reservoir and the water height.

*****

Engineering properties and bearing capaci ty of Malaysian rocks.

Chan Sin Fatt, Dept. of Civil Engineering, University of Malaya.

The engineering properties of Malaysian Limestone and Granite as determined from unconfined uniaxial Compression Tests are presented. The properties dealt with are the stress-strain relation~ compressive strength~ deformation modulus~ and Poisson's ratio. A comparison is made between the above properties in the three orthogonal directions x~ y~ z.

The two common problems in the design of pile foundations in limestone areas: namely~ bearing capacity of the rock and presence of cavities~ are also discussed.

*****

Preliminary studies on the correlation of index properties and engineering properties of some Malaysian rocks.

Tan Boon Kong, Dept. of Geology, National University of Malaysia & Chan Sin Fatt, Dept. of Civil Engineering, University of Malaya.

Ten different rocks obtained as drill cores from various locali-ties in Malaysia were tested in the laboratozry for their index and engineering properties. The rock properties investigated include the dzry density~ the Shore scleroscope hardness, the point load strength index and the unconfined compressive strength. An attempt was made to correlate these properties so as to enable one to prediCJt the uncon-fined compressive strengths of rocks based on results of the more easily carTied out index tests (such as the Shore hardness and/or

76

to 550 NE~ spaced 0.03 m to 1.0 m with an average spacing of 0.2 m to 0.5 m.

Diamond d:r>il Zing up to a depth of 75.0 m in the damsite indicated average joint spacings to vary from 0.1 m to 3. 0 m~ with most lying between 0.5 m to 1.0 m. ~ese joints a~ not normally continuous over long distances. A number of rehealed~ sheared and brecciated zones have been intersected by drilling.

Principal dimensions of project

Kenyir Dam: Type: Earth and rockfiU Crest Level: EL 155 m Dam Crest Length: 800 m Height of Dam: 150 m 6 3 Volume of Dam Embankment: 15.2 x 10 m

Storage Reservoir: Full Supply Level: EL 145 m Minimum Operating Level: EL 120 m Maximum Flood Level: EL 153 m Gross Storage Volume 6 3 at F.S.L.: 13~600 x 1~ ~ Live Storage Volume: 7~400 x 10 m Surface Area at F.S.L.: 36~900 hect~s.

Power Station: Number and Rated Capacity of Units: 4 x 100 MW.

*****

Some observations on blasting practices in Malaysia.

Tan Boon Kong, Dept. of Geology, National University of Malaysia, Kuala Lumpur.

The paper is based on the author's observations of blasting practices in quarries and road cuts in Malaysia. Some common blasting problems are identified and discussed~ such as the problems of over-break~ toe problem~ flyrock~ insufficient fragmentation resulting in oversized boulders~ safety~ etc. Many of the problems discussed are attributed mainly to the fact that most personnels (blasters and project engineers) involved in blasting operations unfortunately lack the basic training and understanding in the basic principles of explosives engineering. Blasting is therefore carried out in an ad hoc manner guided by practical experience on ly.

~e basic properties of explosives~ influence of geological factors and the general principles for the design of blasting rounds ~ also discussed.

*****

Rehabilitation of mining land at Conzino RiDtinto Malaysia Sdn. Bhd. Kuala Langat, Selangor.

Choy Kam Wai, Conzino Riotinto Malaysia Sdn. Bhd., Kajang, Selangor.

Dredge tailings and land disturbed by mining are returned to

75

point ~oad tests).

Various test methods are a~so brie~y discussed~ inc~uding the effect of variation of samp~e ~ength/diametep patio in the point wad test.

*****

The brittle failure behaviour of two isotropic granitic roCks.

Ibrahim Komoo, Dept. of Geology, National University of Malaysia.

Britt~e fai~ure behaviour of two granite rocks~ having more 01' ~ess the same minepa~ogy~ but differing in grain size~ wepe investi-gated undEp unia:x:ia~ comppessive ~oading. TNhite~ mediwn-gmined granite behaved as a pure~y e~astic materia~ during initia~ ~oading~ becoming p~astic befo1'e fina~ britt~e fai~ure. Pink~ coapse-gpained granite showed the same chapacteristics as the white gpanite during ini tia~ loading ~ however ~ during the advance stage 0 f ~oading ~ it showed stpain hardEning behaviour before britt~e fai~ure.

FuPthermope~ the white granite showed a negative vo~umetric stpain during ma:x:imum comppessive stress~ whereas~ the pink gpanite indicated a zero vo~wnetric stpain during ma:x:irrrum comppessive stpess.

*****

Engineering geology of the Kenyir Damsite, Trengganu.

Chow Weng Sum, Geological Survey of Malaysia, Ipoh, Perak.

The Tzoengganu ~vep Basin Deve~opment Project is undEptaken joint~y by the Ma~aysian GOvernment and the Snowy MOuntains Engineering Cortpomtion of Australia for the construction of a mu~ti-purtpose rock-fill dam.

The proposed dam is ~ocated a~ong Sungai Tpengganu just be~ow the con~uence of Sungai Trengganu - Sungai Kenyip. The dizmsite is undEp~ain by a. medium to coarse gmined biotite gpanite. NU1'I'erous out~rops are particu~ar~y preva~ent beZow the ~ood ~eve~ on the Pightbank. These outcrops are a~so found a~ong many of the minor creeks on eithep banks. Large ~ands~ides on .the va~~ey s~opes have ~eft many e:x:posed rock faces. Landslide dEbPis in the form of ~arge accumu~ations of earth and bouZdeps· are oorrmon on both banks ~ e:x:pecia~~y on the ~eft bank. Do~erite dykes~panging from a few centimetres to sevepa~ metres in widthtJ are common and strike ge;Jemlly from 0350 to 0'100 and dip '10 . SE through vertical, to 80 NW. .

Open sheet joints are common~y observed al,ong rock faces. Apart from sheet joints~ thepe are another 2 majop sets of joints. They are: i) strik~ng ~m 0300 to 0'100; dipping '100 SE through vertica~

to '15 NW~ spaae~ 0.6 m .. to 1.6 m and form rock faces up to 100 m l,ong;

ii) striking ~m 1100t~· 16Qo; dipp~ng 65 0 SWthrough veptical,

., 77

. produative agriau'Ltuml tand-use as paPt of Company policy. Disturbed land 'bJas classified. Topography 'bJas re-shaped to one conducive to agriaul ture and drainage was improved. Experiments were carried out successfUlly and the best adapted agriaultuml species 'bJere identi~ed for fUrther planting. Soil analysis 'bJas the basis by 'bJhich the ground 'bJas ameliorated to produce a suitable soil. The pZan invoZves the introduction of ruminants 'bJhich 'bJiZZ increase soil, fertiUty by compZeting a beneficial, nutrient cycZe. Thus~ from a fresh-,uater 8'/.rJamp~ the Zand is transforrred to produative agriaulturaZ use after mining.

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Sequential aerial photography in coastal dynamics.

J.K. Raj, Dept. of Geology, University of Malaya, Kuala Lumpur.

The importance of sequential, aerial, photographs as a tool, of monitoring coastal, changes is disCU8sed~ 'bJith a studY of the shoreUne changes of KeZantan State as an exampZe.

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The application of photoelastic coating technique in rock mechanics research.

Ibrahim Komoo, Dept. of Geology, National University of Malaysia, Kual a Lumpur.

In the past three decades or so~ the classical, photoeZastic technique was used intensiveZy in rock mechanics research. However~ the technique was Zimited to model, anaZysis. The question here is whether the model, represented the actual rock or not?

In recent years~ the photoelastic coating technique was deveZoped in the fieZd of experimental, stress anaZysis. The appUcation to rock rnechanics~ so far~ is stiU very Umited. In this paper~ the author 'bJishes to discuss sorne potential, and advantages of this technique in rock mechanics research.

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Use of the finite element method in geomechanics.

Tan Boon Kong, Dept. of Geology, National University ef Malaysia, Kuala Lumpur.

The finite eZernent method is a potrJerfuZ numerical, rrethod usefUl, in soZving a wide speatrum ofprobZems in geomechanics. Its use~ in fact~ is not Zimited to geornechanics onZy. It has aZso been used extensiveZy in struaturaZ analysis~ grounawater fl,0'LrJ~ heat fl,0'LrJ problems~ etc.

The principZe of the rrethod~ its Umitations and potentials are briefl,y discussed and illustrated by several practical, applications.

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78

NEW S o F THE SOC I E T Y

New Library Additions

1. 2.

3. 4. 5. 6.

7.

The following publications were added to the Library of the Society:

Oklahoma Geological Survey, B127, 1979. The University of Kansas, Palaeontological contributions, article 64 and 65, 1979. World data Center A for Solid Earth Geophysics, Rep. SE-20, 1979. AGID News, no. 21, 1979. Commonwealth Geological Liaison Office, nco e, 1979. SEATRAD Centre: Seminar on drilling and sampling 6-8th Sept. 1979 -9 papers. Acta Palaeontologica Sinica, V. 18, no. 4, 1979.

8. Palaeontologica Sinica, new series B, no. 13, 1979. 9. Geological Report of the Hiroshima University, no. 22, 1979. 10. IMM Transactions/Sect. C, V. 88, June 1979. 11. National Library of Singapore, adult reference collections,

accessions list, Aug, 1979. 12. IMM Bulletin 874 & 875, 1979. 13. Oklahoma Geology notes, V. 39, nos. 1-3, 1979. 14. National Library of Singapore, Senarai Tokoh - Tokoh Kenamaan. 15. Geological Survey of New South Wales, nos. 40, 44, & 38, 1979. 16. Mine data sheets to accompany metallogenic map Cootamundra,

1:250,000 sheet S155-ll, 1979. 17. Exploration geophysics, 1979 by T.N. Crook.

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Membership

The following persons have joined the Society:

Full Members

1. Mohd. Zuhudi Muda, Geology Dept., University of Malaya, Kuala Lumpur. 2. Mohd. Zain Hj. Yusuf, Dept. of Soil Mechanics & Geology, Fac.

of Civil Engineering, Universi ti Teknoloji Malaysia, Kuala Lumpur.

Associate Member

1. Mrs. Leong Sau Heng, Dept. of History, Arts Faculty, University of Malaya, Kuala Lumpur.

Institutional Member

1. Amdex Mining Ltd., P.O. Box 147, North Sydney, NSW 2060, Australia.

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Change of Address

The following members have informed the Society of new addresses as indicated:

Ahmad Tajuddin, 27 Highbury Place, Leeds 6, England.

79

K. Kawada, No. 305, Higashi I Chome 1-3, Yatabe-cho, Tsukuba-gun, Ibaragi-Ken, Japan.

Teh Guan Hoe, Dept. of Geology, University of Malaya, Kuala Lumpur.

Shunso Ishihara, Geological Survey of Japan, Higashi 1-1-3, Yatabe-Cho, Tsukuba-gun, Ibaraki, Japan 305.

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o THE R NEW S

Ninth Annual Convention of the Indonesian Petroleum Association

The Ninth Annual Convention of the Indonesian Petroleum Association will be held on May 27th - 28th, 1980 at the Borobudur Intercontinental Hotel.

Lecture presentations to be given at the Technical Sessions of the Convention will deal with exploration, production, operations and economics. Members with presentations that would be of significant interest and importance to the petroleum industry in Indonesia should write to

Indonesian Petroleum Association Lecture Committee Jalan Menteng Raya 3 Jakarta, Indonesia.

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New and forthcoming books in Earth Sciences from Pergamon Press Ltd.

Members interested in the literature of these publications can write for details to

Marketing Assistant Pergamon Press Ltd Headington Hill Hall, Oxford OX3 OBW England.

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Travel grants for geoscientists

The Regional Office for Science and Technology for Southeast Asia (ROSTSEA) of UNESCO, within the framework of the "Regional Network for Geosciences in Southeast Asia", and with the financial assistance of the "Association of Geoscientists for International Development" (AGID) , is giving three travel grants to geoscientists to carry out study or exchange visits, for periods of one to three months, to institutions and projects in the field of the earth sciences in Asia.

Each travel grant, consisting of an air ticket and a lump sum living allowance, is limited to a monetary value not exceeding

US$1800. The actual grant will be made on the basis of the cost of

80

the air ticket and the planned length of the visit. ~ Each candidate for a grant must have worked out his own detailed

programme for a study visit. The visit must be completed before 1 September 1980. At the conclusion of the visit the candidate must submit a detailed report to Unesco.

Candidates wishing to apply for these travel grants must submit to the Director of Unesco, ROSTSEA, the following documents:

a) summary of education accomplishments and work experience; b) detailed statement of the purpose and programme of the proposed

study visits; c) evidence that the host institutions or project agrees to the

proposed programme.

Unesco will accept applications on a first come first served basis but only up to 31 March 1980.

For further information, please write to:

Calendar

Dr. V. Prakash Director, ROSTSEA Jl. Thamrin 14 Tromolpos 273/JKT Jakarta, Indonesia.

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Under this column the Society will note coming events on meetings, courses and symposia of interest to members. Date in parenthesis gives the issue of Newsletter containing more information pertaining to the events:

Other events 1979 1979 :f.

Sep 17 - 22

Sep 18 - 21

Oct 15 - 18

Oct 28 - Nov 2

14th Congress of the Pacific Science Association USSR. B.G. Gafurov, Chairman of the Soviet National Pacific Commi ttee, Academy of Sciences of ·the USSR, Moscow. (Jul-Aug, 1977).

AAPG - SEG stratigraphic interpretation of seismic data. AAPG Education Dept., P.O. Box 979, Tulsa, Oklahoma 74101, USA.

CCOP/SOPAC Symposium on 'Petroleum Potential in Island AlICS, Small Ocean Basins, Submerged Margins, and Related Areas, Suva, Fiji'. CCOP/SOPAC Technical Secretariat, c/o Mineral Resources Dept., Private Main Bag, GPO, Suva, Fiji. (Jan-Feb, 1979).

Law of the Sea Institute: Thirteenth Annual Conference. Law of the Sea Institute, University of Hawaii, 2540 Dole Street, Holmes 401, Honolulu, HI 96822. (Mar-Apr 1979).

ICOLD XIII Congress on Large Dams, New Delhi. C.V. J. Varma, Organizing Secretary, XIII Congress on Large D.ms, c/o Central Board of Irrigation and Power, Kasturba Ghandi Marg, New Delhi, 110001, India.

Oct 29 - Nov 1

Nov 17 - 21

Nov 20 - 21

Dec 13 - 16

Dec 17 - 19

1980 Jan 7 - 10

Feb 11 - 16

Feb 14 - 17

Feb 25 - 26

Mar 4 - 6

Mar 24 - 28

Apr 7 - 11

81

AAPG Diagenetic controls on carbonate porosity evolution. AAPG Education Dept., P.O. Box 979, Tulsa, Oklahoma 74101, USA.

X World Mining Congress, Istanbul. The Turkish National Committee of the World Mining Congress, Ziya Gokalp Caddesi, No. 17, Kat 8, Ankara, Turkey.

National Symposium on the availability of strategic minerals, London, U.K. The Secretary, Institute of Mining and Metallurgy, 44, Portland Place, London, WIN 4BR. (May-Jun 1979).

Problems of mineralisation associated with acid magmatism, Exeter, U.K. (M. Stone, Dept. of Geology, University of Exeter, North Park Road, Exeter, England).

Evolution of India-Pacific plate boundaries, (workshop and symposium), Sydney, Australia. (Convenors, Dept. of Geology & Geophysics, University of Sydney, Sydney, NSW 2006, Australia).

International Conference on Engineering for Protection from Natural Disasters, Bangkok, Thailand. Conference Secretary, lCEPND, Div. of Geotechnical and Transpor-tation Engineering, AIT, P.O. Box 2754, Bangkok, Thailand.

Fifth Gondwana SympOSium, Wellington, New Zealand. Symposium and field trips. C.J. Burgess, Fifth Gondwana Symposium, Victoria University of Welling-ton, Private Bag, Wellington, New Zealand. (May-Jun 1978).

Interdisciplinary Conference on Earthquake Prediction Research in the North Anatolian Fault Zone, Instanbul, Turkey. A. Vogel, Instit fur Geophysi-kalische Wissenschaften, Freie Universitat Berlin, Rheinbabenalle 49, 1000 Berlin 33, F.R.G.

Time Scale Symposium, London, U.K. Secretary, Geological Society, Burlington House, Piccadilly, London, WI, U.K.

Petroleum Geology of the Continental Shelf of North-West Europe, London, U.K. Miss I. McCann, Conference Officer, London, WlM 8AR, U.K.

AAPG Petroleum Reservoir Fundamentals School. AAPG Education Dept., P.O. Box 979, Tulsa, Okla. 74101, USA.

International symposium on landslides 'ISL 1980' , New Delhi. Dr. R.K. Bhandari, Organising Secretary, ISL 1980, P.O. Central Road Research Inst., New Delhi, 110002, India.

Apr 10 - 15

May 12 - 14

May 12 - 16

May 27 - 30

Jun 25 - 27

Jun 29 - Jul 6

Jul 4 - 7

Jul 7 - 17

Jul 14 - 24

Jul 29 - Aug 10

Sep 8 - 13

82

8th International Geochemical Exploration Symposium, Hannover, Fed. Rep. Germany. Dr. H. Gundlach, Organising Committee, 8th International Geochemical Exploration Symposium, P.O. Box 51 01 53, D-3000 Hannover 51, F.R.G. (Jul-Aug 1978).

Conference on Soil Science and Agricultural Develop-ment in Malaysia. Secretary, Executive Committee, Conference on Soil Science and Agricultural Develop-ment, P.O. Box 2644, Kuala Lumpur, Malaysia. (Jul-Aug 1979).

International Archaean Symposium, Perth, Australia. Sponsored by IGCP Archaean Geochemistry project and Geologic,al Society of Australia. (J .A. Hallberg,

Archaean Symposium, CSIRO, Division of Mineralogy, Private Bag, Wembly, Australia 6014).

National and International Management of Mineral Resources. The Secretary, Institute of Mining and Metallurgy, 44 Portland Place, London WIN 4BR, U.K. (Mar-Apr 1979).

Fore-Arc Sedimentation and Tectonics in Modern and Ancient Subduction Zones, London, U.K. J.K. Leggett, Department of Geology, Imperial College, Prince Consort Road, London, SW7 2AZ, U.K.

Fifth International Palynological Conference, Cambridge, England, U.K. Conference with field excursions. (Mrs. G.E. Drewry, Dept. of Geology, Sedgwick Museum, Downing Street, Cambridge, CB2 3EQ, England) .

General meeting of the International Mineralogical Association (IMA), Orleans, France. Scientific & poster sessions, field excursions. (Secretariat de la l2eme Assemblee Generale de I'IMA, B.R.G.M., BP 6009, 45018, Orleans, Cedex, France).

26th International Geological Congress, Paris, France. Paul Sangnier, Seeretaire General du 26eme C.G.I., Maison de la Geologie, 77-79 rue Claude-Bernard, 75005, France. (Nov-Dec 1977).

International Symposium on water-rock interaction, Edmonton, Alberta, Canada. Sponsored by IAGC and the Alberta Research Council. (B. Hltchon, Alberta Research Council, 11315, 87th Avenue, Edmonton, Alberta, Canada T6G 2C2).

Second European Conodont Symposium (ECOS II), Austria and Czeckoslovakia. Symposium with pre- and post symposium field trips co-sponsored by the Geological Survey of Austria and Geological Survey of Czecho-slovakia. (ECOS II, Geological Survey of Austria, P.O. Box 154, Rasumofskygasse 23, A-l031, Vienna, Austria.).

World Conference on Earthquake Engineering, Istanbul, Turkey. A. Gurpinar, Secretary, 7 WCEE, Yuksel Caddesi 7/B, Ankara, Turkey.

Sep 17 - 19

Oct 5 - 8

Sometime in 1980:

1981 Mar 29 - Apr 4

83

Eurotunnel '80, Basle, Switzerland. Cbnference on Tunnelling in Europe. (Secretary, Institute of Mining and Metallurgy, 44 Portland Place, London, WIN 4BR, U.K.).

Complex sulphide ores, Rome, Italy. Organised by IMM in association with Consiglio Nazionale delle Ricerche (Laboratorio per il Trattamento del Minerals). The Secretary, IMM, 44 Portland Place, London WIN lBR, U.K.).

Workshop on Fission Track Dating by the Geoscience Network. Prof. B.K. Kim, Executive Secretary, Geoscience Network, Seoul National University, Seoul, South Korea.

International Conference on Arid Soils - Properties, Genesis and Management, Jerusalem, Israel. Inter-national Conference on Ar.Ld Soils- Properties, Gen~sis and Management, P.O. Box 3054, 122 Hayarkon St., Tel Aviv, Israel. (May-Jun 1979).

*****